Density Functional theory investigations on the geometrical and electronic properties and growth patterns of Sin (n = 10–20) clusters with bimetal Pd2 impurities

Abstract The geometrical and electronic properties and growth patterns of the bimetal Pd 2 doped Si n (n = 10–20) clusters have been studied systematically by density functional theory. The growth-pattern behaviors, relative stabilities, and chemical bonding of these clusters are presented and discussed. The optimized geometries exhibit that the dominant growth patterns of Pd 2 Si n (n = 10–20) are based on the pentagonal prism PdSi 10 . The bimetal Pd 2 is doped on the opened cage-like silicon clusters (Si n ) with the range of size n = 10–15, while doped on bigger silicon clusters (Si n , n = 16–20), the Pd 2 are completely encapsulated inside Si n frames. The geometrical configurations of the encapsulated Pd 2 in the Si n frames are varied due to the interactions between Pd 2 and Si n frames. The calculated fragmentation energies reveal that the remarkable stable Pd 2 Si n clusters with n = 11, 13, 16, 18, and 20 are observed. Among all different-size clusters, the Pd 2 -doped Si 16 is the most stable cluster. Particularly, the cage-like Pd 2 Si 16 geometry is obviously distinct as compared to the single transition metal doped silicon cluster. Interestingly, the critical size of geometry transition is explored at n = 16. Natural population analysis manifests that the charge-transfer phenomena in the Pd 2 -doped Si n clusters are similar to those of the single TM doped silicon clusters. In addition, the Pd 2 Si n (n = 10, 13, 14, 16, and 17) isomers have enhanced chemical stabilities because of their larger gaps between the highest occupied orbital and the lowest unoccupied orbital.